Momentum and Impulse Momentum Momentum can be defined as "mass in motion." All objects have mass; so if an object is moving, then it has momentum Momentum depends upon the variables mass and velocity Momentum = mass * velocity p=m*v where m = mass and v=velocity Momentum is a vector quantity
To fully describe the momentum of a 5-kg bowling ball moving westward at 2 m/s, you must include information about both the magnitude and the direction of the bowling ball p=m*v p = 5 kg * 2 m/s west p = 10 kg * m / s west Elastic and inelastic Collisions When a Ball hits the ground and sticks, the collision would be totally inelastic
When a Ball hits the ground and bounces to the same height, the collision is elastic All other collisions are partially elastic collision Check Your Understanding Determine the momentum of a ... 60-kg halfback moving eastward at 9 m/s. p = mv = 60 kg ( 9 m/s ) 540 kg *m /s east Given: m = 60Kg
v= 9 m/s 1000-kg car moving northward at 20 m/s. p = mv = 1000 kg ( 20 m/s ) 20,000 kg *m /s north Find : momentum (p) Given: m = 1000Kg v= 20 m/s Momentum and Impulse Connection
To stop such an object, it is necessary to apply a force against its motion for a given period of time J = Ft = m v e g n a h C = e
s l u Imp m u t n e in mom
Check Your Understanding If the halfback experienced a force of 800 N for 0.9 seconds to the north, determine the impulse Given: F = 800 N J = F t = m v t = 0.9 s Find : 800N ( 0.9s ) = 720 N*s Impulse (J) the impulse was 720 N*s or a momentum change of 720 kg*m/s
Impulse Question #2 A 0.10 Kg model rockets engine is designed to deliver an impulse of 6.0 N*s. If the rocket engine burns for 0.75 s, what is the average force the engine produces? Given: t = .75 s J = F t = m v J = 6.0 N*s 6.0 N*s = F ( 0.75s ) Find : 6.0 N*s/ 0.75s = F
Average 8.0 N = F Force Impulse Question # 3 A Bullet traveling at 500 m/s is brought to rest by an impulse of 50 N*s. What is the mass of the bullet? Given: v = 500 m/s J = F t = m v J = 50 N*s 50 N*s = m ( 500 m/s 0 m/s Find
) : 50 kg-m/s 2 *s / 500 m/s = m m = ? .1 kg = m Summary the impulse experienced by an object is the force*time the momentum change of an object is the mass*velocity change the impulse equals the momentum change
"It is as if the mind and feelings vibrate at a certain frequency and are most satisfied with music that is attuned to that frequency" (Helen Bonny) "Music is your only friend - until the end" (Jim Morrison) E. Clarke:...
Benzene, C6H6 The bond lengths in the ring are identical, and between those of single and double bonds. Resonance Bond Length and Bond Energy Resonance bonds are shorter and stronger than single bonds. Resonance bonds are longer and weaker than...
The pKa of the -protons of aldehydes and ketones is in the range of 16-20 (Table 18.1, p. 754) ethane acetone ethanol pKa= 50-60 pKa= 19 pKa= 16 inductive effect resonance effect pKa 19 14 16 9 acid base conjugate...
The smaller the grain size, the fewer dislocations in the pile up and the higher the applied stress to cause further slip. So the smaller the grain size the higher the mechanical strength (111) s 45o 30o Hall Petch Equation...
Le coût de la manque de confiance, le coût de soupçon. Personne ne veut prendre le risque de coopérer, car ils ne peuvent pas compter sur la cooperation d'autrui. Nous nous retrouvons souvent dans des situations semblables - avec nos...
Insects Are Arthropods. Insects are the largest group of Arthropods. Jointed. appendages (bendable) Segmented. bodies. Exoskeleton. of Chitin that must be molted to grow. Related to . spiders, ticks, scorpions, millipedes, crustacean
The Great War: The World in Upheaval. Dissident cartoonist Walter Trier's satirical map of Europe in 1914. Trier's work stands in stark contrast to the press of the time, which fueled the chauvinist desires of competing national publics.